The islands were closed while colonies of brown pelicans, skimmers, terns and other birds built nests, hatched eggs and raised chicks.

Fishing was allowed in waters around the islands, which have been significantly eroded by storms. Any disturbance of nesting birds is prohibited.

Supervisory Park Ranger Byron Fortier says crews also cleaned more oil from last year's Deepwater Horizon oil spill from the beaches during spring and early summer. He says spill remnants no longer threaten wildlife in these areas.

The spill closed the refuge entirely for eight months, starting in early May 2010. The islands reopened in January but were closed in mid-March to limit disturbance to the birds.

Established in 1904, Breton is the second-oldest national wildlife refuge. It includes the Chandeleur Islands and other barrier islands off of St. Bernard and Plaquemines parishes in southeast Louisiana.